Prevalence of intestinal protozoan parasites (Giardia, Cryptosporidium, Blastocystis and Enterocytozoon) in animals from Qinghai-Tibetan Plateau area, China.

Giardia duodenalis, Cryptosporidium spp., Blastocystis sp., and Enterocytozoon bieneusi are prevalent zoonotic intestinal parasitic protozoans that cause diseases in humans and various animals. In this study, a total of 319 fresh fecal samples from domestic and wild animals collected from the Qinghai-Tibetan Plateau Area (QTPA), China, were examined. The results showed that the overall prevalence of these four protozoa in this region was 6.6% (21/319). Specifically, the infection prevalence of G. duodenalis, Cryptosporidium spp., Blastocystis sp., and E. bieneusi was 3.4% (11/319), 1.3% (4/319), 1.9% (6/319), and 0% (0/319), respectively. Three G. duodenalis assemblages, A (n = 1), E (n = 4) and F (n = 1), and two zoonotic Cryptosporidium spp., C. ubiquitum and C. alticolis, were identified. Regarding Blastocystis sp., only one subtype (ST1) was identified in root vole (Microtus oeconomus), a potentially zoonotic subtype. PCR amplification at the internal transcribed spacer (ITS) locus did not detect E. bieneusi in any of the samples. This study provides fundamental data on these four pathogens in M. oeconomus and other domestic animals in the QTPA, China. Although the prevalence of the four parasites was relatively low, the zoonotic species C. ubiquitum and G. duodenalis assemblage A were identified, indicating that wild animals and domestic animals might act as potential reservoirs in the transmission between humans and animals. Further studies are needed to better understand the epidemiology of parasites in wild animals in the QTPA and their potential public health implications.